EVERGLADES NATIONAL PARK, Fla.  The man leading efforts to eradicate giant Burmese python snakes from Everglades National Park sounds almost fearful, and certainly not optimistic, when he talks about the chances of wiping out an invasive species he calls "the enemy."

That is partly because Skip Snow, a 54-year-old veteran wildlife biologist with the U.S. National Park Service, says he doesn't know how many of the slithery monsters are in the swampy Florida park.

"It could be literally thousands," Snow told Reuters. "It could be a number I don't want to know. It could be scary."

It's scary indeed, especially since one of the creatures was aggressive enough to try devouring a 6-foot alligator in the park last year. The alligator is believed to have been dead already and the snake also died trying to digest it.

There have been other encounters between pythons and alligators but the gators, which are pretty tough customers, aren't what Snow is worried about.

What keeps him up at night is the threat the prowling pythons pose to a delicate subtropical wildlife haven with a whole catalogue of rare or endangered native species.

The pythons, with their razor-sharp teeth, have been eating practically everything that moves in the park, from small mammals to large wading birds, said Snow.

The first Burmese pythons sighted in the park's savanna and steamy swamps, back in the mid-1970s, are thought to have been pets.

The snakes, which are native to Southeast Asia, can be purchased legally in the United States. But many owners, especially so-called impulse buyers, tend to release them in places like the Everglades once they realize they can grow from just a foot to about 12 feet long in their first two years of life.

Dumping reptiles is illegal and Florida lawmakers are currently mulling stiffer penalties, including possible jail time. The state will also hold its first "snake amnesty day" on May 6, for anyone who might want to dispose of their Burmese pythons or other members of the Boa family legally.

"A BREEDING POPULATION"

If irresponsible pet owners were the only source of the pythons invading Everglades National Park, Snow might not face such a daunting challenge.

Compounding his eradication problems, however, is the fact that the bone-crushing snakes are also breeding in the wild.

"There's every evidence that the problem is increasing in scope and scale," said Snow. "We have a breeding population. They're now breeding within Everglades National Park."

A total of 212 Burmese pythons have been killed or removed from the park or adjacent lands since 1995, including 95 last year alone.

But that is surely just the tip of the iceberg and Snow, who has spent the last few years on the park's python eradication program, readily acknowledges that his efforts are only just beginning to get under way.

He recently experimented with a beagle puppy nicknamed "Python Pete," using him to ferret out the snakes and said he also had some recent success with "Judas snakes" -- using pythons implanted with radio transmitters to track down other pythons.

The puppy, incidentally, was kept on a leash to prevent him from becoming what a Park Service newsletter described as "a snake snack."

Florida authorizes state law enforcement officers to shoot pythons and wildlife officials "euthanize" those they catch.

"We can probably see control," said Snow, suggesting that one of the world's largest snakes can be prevented from totally overrunning the park.

"I don't think we've got a very good assessment of whether or not we can eradicate," he added, however.

Scott Hardin, exotic species coordinator for the Florida Fish and Wildlife Commission, was also pessimistic when asked about the chances of stomping out pythons or other non-native animals that run wild in parts of the southernmost U.S. state. The invaders include dragon-like, Nile monitor lizards and racoon-sized African rats.

"Rarely do you have a chance to eliminate anything, almost ever. Control is pretty tough, so what we really want to do is our utmost in prevention and education," Hardin said.